The present invention relates to vehicle occupant restraint systems and more particularly to passive type safety belts wherein the belt is automatically positioned about the occupant as the occupant enters the vehicle and closes the door.
For many drivers and occupants of motor vehicles, a passive seat belt system is the most desirable inasmuch as the system is self-deploying upon entry to and exit from the vehicle. That is, as the occupant enters the vehicle and closes the door, the passive restraint system is automatically positioned to restrain the occupant in the event of an emergency stop or accident. Upon exit, the passive restraint system automatically removes itself.
Another feature desirable to many vehicle owners and operators is the inclusion in the restraint system of automatic adjustment for various size individuals. This is often particularly of interest in safety belt systems associated with the passenger seat where different people of different sizes many be moving in and out throughout the day.
One recent passive type restraint system is shown in the copending application of Avraham Ziv and William Hollowell entitled "Vehicle Sensing Inertia Reel Lockup Inhibitors," Ser. No. 872,306, filed Jan. 25, 1978 and assigned to the common assignee of this application. The system disclosed therein utilizes two different methods for the restraining of the upper and lower torso as has been found to be highly desirable. That is, a tensioned/lockable restraining belt system is employed across the upper torso to prevent the forward rotational movement thereof about the hip joint and a shaped pad on the dashboard of the car is employed to prevent "submarining" of the lower torso (i.e., sliding under the dash).
For various reasons such as user preference, builder preference, and applicable safety regulations, the freedom of movement which such a combined system as that of the foregoing application provides cannot always be utilized and a combined positive lap and upper torso belt system must be employed. Typically in such instances, the system employed is a so-called "three-point" system wherein a pair of belts are connected on one end to a fastener on one side of the body of the occupant extending therefrom across the lap and upper torso respectively to a pair of strategically located fasteners on the opposite side of the occupant.
A passive upper torso restraining belt as shown in the aforementioned copending application extending from a point above the occupant's out-board shoulder on the door to a point adjacent the occupant's in-board hip joint provides no hinderance to the entry and exit of the occupant inasmuch as the occupant's legs slide easily underneath the upper torso belt and the upper torso belt moves ahead of the body of the occupant during entry. By contrast, however, the addition of a lap belt portion extending from the lower door on one side to the same point in-board of the occupant causes the lap portion of the belt to droop across the opening of the door blocking entry thereto and requires two hands to enter or exit the vehicle--one to operate the door and one to lift the lap belt portion of the "passive" belt system.
Attempts at providing a workable passive lap belt not requiring such lap belt maneuvering are not new. The attempts to date, however, have attained whatever success was attained therein through the use of simple to complicated mechanical mechanisms operably carried by the seats, door, body, and/or dashboard of the vehicle in various permutations and combinations. Some relevant examples as shown in U.S. Pat. Nos. are as follows:
3,895,824 (Bauer et al) employs a lever pivotally mounted in the door of the vehicle for positioning the belt.
3,976,305 (Fieni) discloses a pneumatically or hydraulically operated variable length arm connected for actuation by the movement of the door to physically move the belt away from the door opening.
3,583,726 (Lindblad) discloses an arm carried by the door for moving the belt into and out of position as the door is closed and opened.
3,796,442 (Mauron et al) discloses a hydraulically operated arm for positioning the belt.
3,840,249 (Strom) shows another positioning mechanism employing a movable track mechanism.
3,850,446 (Hogensen) utilizes a spring loaded arm for positionally moving the belt.
In addition to the entry/exit problem, three-point systems in the past have either been of the fixed length or tensioned upper torso belt type. In the fixed length type, the length of the upper torso belt must be adjusted to the proper length for comfort by each occupant. Such a procedure is bothersome to many people--which lead to the development of the tensioned system. The tensioned system is similar to that described in the aforementioned copending application Ser. No. 872,306 wherein the upper torso belt is held by a spring-loaded spool in tension against the upper torso of the occupant. As the occupant moves, the belt protracts and retracts from the spring tension. The belt is locked against protraction in an emergency condition by an inertia sensing mechanism. Inasmuch as many people find the tensioned upper torso belt a bother, many such systems are provided with a slidable stop mechanism on the belt to provide slack by stopping the belt from retracting onto the spool past a selected point. Again, this mechanism requires adjustment and can be a source of bypassing the protection the belt provides if too much slack is maintained.
Wherefore, it is the object of the present invention to provide a passive safety belt system employing a lap portion wherein the lap portion is positionally disposed for ease of entry to and exit from the vehicle without the necessity for mechanical positioning devices as employed in the prior art to date.
It is a further object of the present invention to provide a three-point safety belt system which is automatically adjustable to various occupant sizes while providing a tight lap belt portion and a non-tensioned upper torso portion when the system is deployed.